I own them both and use them in my PBA Experience league.
My Primal Scream is drilled with the pin below ring finger and cg is kicked out maybe 3/4" with a P4 hole. Primal Rage is pin above ring finger with no balance hole. My PAP is 5" over and 0 up/down.

Primal Scream is at 2000 abralon and Primal Rage is OOB. They are same age and roughly the same number of games as I purchased them together.

Both balls have their place and make an excellent combo. The Primal Scream is awesome on the fresh with a good read of the mid lane and has a nice controlled finish. When the pattern transitions and I need to move left and play a deeper angle, the Primal Rage comes out and gives me a very nice look. It gives good length and big left hand turn when it hits the friction.

I think I would choose the Primal Scream if I had to settle on just one of them, but with the same drilling and surface, the Primal Rage would probably work just as well.

Hope that helps.

I think the one thing to also consider here is how are the backends at the house you usually bowl at? If they're nice and crisp and stay that way, go with the scream. If nothing really turns hard on the back, I would go rage.

My train of thought here is that between the two the only possible problem would be if the backends aren't jumpy enough to carry with the screm. If they are jumpy, the rage might be too much flip.

So-good backends, scream
Iffy/spotty backends, rage.

And so you know, I have a rage, and a scream on the way. My house's backends are pretty weak and the rage is great on it.

Matt

The differences between the two balls in 12 lbs will be similar to the differences between the same two balls in 15lbs. On these lighter balls the core becomes less of a deciding factor in predicting reaction shape and the cover becomes more of one. The scream being a solid will still be an earlier rolling ball than the pearlized rage.

I would agree with you if they had the same cores in each in 15 lbs but in 12 they had different cores from each other. Then we would have no clue. Also, comparing one in 15 to one in 12 wouldnt be a fair comparison either. Too many variables.

In this case though, the key difference between the two balls is the coverstock, regardless of what weight.

Matt

Ps- I do get what you're saying. Me saying that my 15lb rage is great on a house shot shouldn't mean anything to him. True. But he's more interested in the comparison in reaction of the rage and the scream, the difference between the two will stay similar as long as the weight is the same in the two you're comparing.

No I know the numbers are greatly different between a 15lb and a 12lb. Its hard to explain what I'm trying to say...

15lb Rage- 2.55, .050 = 15lb Scream- 2.55, .050

12lb Rage- 2.67, .040 = 12lb Scream- 2.67, .040

The difference between the Rage and the Scream (which is what he was asking for) is the same regardless of weight. Right?

If he were to say...how much does this ball hook in 12lbs or...what line can i play I would have no idea, but just comparing the reaction of one to the other, the difference should be similar shouldn't it? Because ultimately, between a 15lb rage and a 15lb scream, and  ALSO between a 12lb rage and a 12lb scream, the difference is the coverstock.

I'm not being a jerk, honestly. Just trying to explain what I mean. Maybe were just not on the same page?

Matt

Here's my take.  I get Matt's points.  Take a Primal Scream for example (1) 15 lb and (1) 12 lb. laid out same.  Put them in a Throwbot with same stats. (ball speed, tilt, axis rotation, revs) on same lane condition.  Would both Primal Scream's 15 and 12 with different core RG and total differential show the same ball motion? <----There is the issue. Now if Jim likes or wants that 12 lb ball motion then there you go that's the valid comparison but who can say they will be the same?  I say they won't be close both 12's will go longer and finish less on the Throwbot with same stats. and lane condition.

Now if Jim is looking for the 12 lb comparison he would need to compare to 12's.  That's my point.  He can't compare to anyone using 15's or even 14's.  If I was Jim I'd think back to if I ever used a high Rg 2.60 ball with a total diff. of .040 and remember if I liked the ball reaction.  That would be more of a valid comparison.  Covers of both Scream and Rage are very strong this also skews the comparison.

Manufacturers aren't using the same cores in lighter equipment because of cost MoRich is the last one that I know of.  Even Mo/Phil's Radical balls have lighter cores in their lighter version of equipment.

Jim--I think, if I am looking at 12 lb. equipment I'd go thru the balls you are looking at and see which ones use the same core many use a lighter light bulb core in their lighter equipment (check your interest in the Melee-different light bulb core than the 14 - 16)  See if the numbers would match up to something I have used in the past.  Majority are going to be in the 2.60 range you might find something with a higher total diff.

Talked to my driller (Anne Marie Duggan) yesterday and she recommends I start with the Primal Scream when I can hopefully return to bowling in approx 3 weeks or so. I was trying to choose between the DV8 Marauder Madness, Brunswick Meanstreak Beatdown, and the Primal Scream and even though she throws a lot of Storm and some Brunswick, she feels the Primal Scream will fit me best to start. She hasn't thrown a Scream or any Motiv ball, but has drilled a few and saw what they did for different style bowlers.